/* -----------------------------------------------------------------------------
- * $Id: GC.c,v 1.15 1999/01/19 17:06:02 simonm Exp $
+ * $Id: GC.c,v 1.45 1999/02/26 17:46:08 simonm Exp $
*
- * Two-space garbage collector
+ * (c) The GHC Team 1998-1999
+ *
+ * Generational garbage collector
*
* ---------------------------------------------------------------------------*/
#include "DebugProf.h"
#include "SchedAPI.h"
#include "Weak.h"
+#include "StablePriv.h"
StgCAF* enteredCAFs;
*/
bdescr *old_to_space;
+/* Data used for allocation area sizing.
+ */
+lnat new_blocks; /* blocks allocated during this GC */
+lnat g0s0_pcnt_kept = 30; /* percentage of g0s0 live at last minor GC */
+
/* -----------------------------------------------------------------------------
Static function declarations
-------------------------------------------------------------------------- */
-static StgClosure *evacuate(StgClosure *q);
-static void zeroStaticObjectList(StgClosure* first_static);
-static rtsBool traverse_weak_ptr_list(void);
-static void zeroMutableList(StgMutClosure *first);
-static void revertDeadCAFs(void);
+static StgClosure * evacuate ( StgClosure *q );
+static void zero_static_object_list ( StgClosure* first_static );
+static void zero_mutable_list ( StgMutClosure *first );
+static void revert_dead_CAFs ( void );
+
+static rtsBool traverse_weak_ptr_list ( void );
+static void cleanup_weak_ptr_list ( void );
-static void scavenge_stack(StgPtr p, StgPtr stack_end);
-static void scavenge_large(step *step);
-static void scavenge(step *step);
-static void scavenge_static(void);
-static StgMutClosure *scavenge_mutable_list(StgMutClosure *p, nat gen);
+static void scavenge_stack ( StgPtr p, StgPtr stack_end );
+static void scavenge_large ( step *step );
+static void scavenge ( step *step );
+static void scavenge_static ( void );
+static void scavenge_mutable_list ( generation *g );
+static void scavenge_mut_once_list ( generation *g );
#ifdef DEBUG
-static void gcCAFs(void);
+static void gcCAFs ( void );
#endif
/* -----------------------------------------------------------------------------
{
bdescr *bd;
step *step;
- lnat live, allocated, collected = 0;
+ lnat live, allocated, collected = 0, copied = 0;
nat g, s;
#ifdef PROFILING
scavenged_static_objects = END_OF_STATIC_LIST;
/* zero the mutable list for the oldest generation (see comment by
- * zeroMutableList below).
+ * zero_mutable_list below).
*/
if (major_gc) {
- zeroMutableList(generations[RtsFlags.GcFlags.generations-1].mut_list);
+ zero_mutable_list(generations[RtsFlags.GcFlags.generations-1].mut_once_list);
}
/* Save the old to-space if we're doing a two-space collection
g0s0->to_space = NULL;
}
+ /* Keep a count of how many new blocks we allocated during this GC
+ * (used for resizing the allocation area, later).
+ */
+ new_blocks = 0;
+
/* Initialise to-space in all the generations/steps that we're
* collecting.
*/
for (g = 0; g <= N; g++) {
+ generations[g].mut_once_list = END_MUT_LIST;
generations[g].mut_list = END_MUT_LIST;
for (s = 0; s < generations[g].n_steps; s++) {
step->hpLim = step->hp + BLOCK_SIZE_W;
step->hp_bd = bd;
step->to_space = bd;
- step->to_blocks = 1; /* ???? */
+ step->to_blocks = 1;
step->scan = bd->start;
step->scan_bd = bd;
step->new_large_objects = NULL;
step->scavenged_large_objects = NULL;
+ new_blocks++;
/* mark the large objects as not evacuated yet */
for (bd = step->large_objects; bd; bd = bd->link) {
bd->evacuated = 0;
step->hp_bd = bd;
step->blocks = bd;
step->n_blocks = 1;
+ new_blocks++;
}
/* Set the scan pointer for older generations: remember we
* still have to scavenge objects that have been promoted. */
* it has already been evaced to gen 2.
*/
{
- StgMutClosure *tmp, **pp;
- for (g = N+1; g < RtsFlags.GcFlags.generations; g++) {
+ int st;
+ for (g = RtsFlags.GcFlags.generations-1; g > N; g--) {
generations[g].saved_mut_list = generations[g].mut_list;
generations[g].mut_list = END_MUT_LIST;
}
+ /* Do the mut-once lists first */
for (g = RtsFlags.GcFlags.generations-1; g > N; g--) {
- tmp = scavenge_mutable_list(generations[g].saved_mut_list, g);
- pp = &generations[g].mut_list;
- while (*pp != END_MUT_LIST) {
- pp = &(*pp)->mut_link;
+ scavenge_mut_once_list(&generations[g]);
+ evac_gen = g;
+ for (st = generations[g].n_steps-1; st >= 0; st--) {
+ scavenge(&generations[g].steps[st]);
+ }
+ }
+
+ for (g = RtsFlags.GcFlags.generations-1; g > N; g--) {
+ scavenge_mutable_list(&generations[g]);
+ evac_gen = g;
+ for (st = generations[g].n_steps-1; st >= 0; st--) {
+ scavenge(&generations[g].steps[st]);
}
- *pp = tmp;
}
}
/* Mark the weak pointer list, and prepare to detect dead weak
* pointers.
*/
- markWeakList();
old_weak_ptr_list = weak_ptr_list;
weak_ptr_list = NULL;
weak_done = rtsFalse;
+ /* Mark the stable pointer table.
+ */
+ markStablePtrTable(major_gc);
+
#ifdef INTERPRETER
{
/* ToDo: To fix the caf leak, we need to make the commented out
*/
scavengeEverything();
/* revert dead CAFs and update enteredCAFs list */
- revertDeadCAFs();
+ revert_dead_CAFs();
#endif
markHugsObjects();
#if 0
/* scavenge each step in generations 0..maxgen */
{
- int gen;
+ int gen, st;
+ loop2:
for (gen = RtsFlags.GcFlags.generations-1; gen >= 0; gen--) {
- for (s = 0; s < generations[gen].n_steps; s++) {
- step = &generations[gen].steps[s];
+ for (st = generations[gen].n_steps-1; st >= 0 ; st--) {
+ if (gen == 0 && st == 0 && RtsFlags.GcFlags.generations > 1) {
+ continue;
+ }
+ step = &generations[gen].steps[st];
evac_gen = gen;
if (step->hp_bd != step->scan_bd || step->scan < step->hp) {
scavenge(step);
flag = rtsTrue;
+ goto loop2;
}
if (step->new_large_objects != NULL) {
scavenge_large(step);
flag = rtsTrue;
+ goto loop2;
}
}
}
}
}
+ /* Final traversal of the weak pointer list (see comment by
+ * cleanUpWeakPtrList below).
+ */
+ cleanup_weak_ptr_list();
+
+ /* Now see which stable names are still alive.
+ */
+ gcStablePtrTable(major_gc);
+
/* Set the maximum blocks for the oldest generation, based on twice
* the amount of live data now, adjusted to fit the maximum heap
* size if necessary.
(int)oldest_gen->steps[0].to_blocks) <
(RtsFlags.GcFlags.pcFreeHeap *
RtsFlags.GcFlags.maxHeapSize / 200)) {
+ heapOverflow();
}
}
}
- } else {
- /* For a two-space collector, we need to resize the nursery. */
-
- /* set up a new nursery. Allocate a nursery size based on a
- * function of the amount of live data (currently a factor of 2,
- * should be configurable (ToDo)). Use the blocks from the old
- * nursery if possible, freeing up any left over blocks.
- *
- * If we get near the maximum heap size, then adjust our nursery
- * size accordingly. If the nursery is the same size as the live
- * data (L), then we need 3L bytes. We can reduce the size of the
- * nursery to bring the required memory down near 2L bytes.
- *
- * A normal 2-space collector would need 4L bytes to give the same
- * performance we get from 3L bytes, reducing to the same
- * performance at 2L bytes.
- */
- nat blocks = g0s0->to_blocks;
-
- if ( blocks * 4 > RtsFlags.GcFlags.maxHeapSize ) {
- int adjusted_blocks; /* signed on purpose */
- int pc_free;
-
- adjusted_blocks = (RtsFlags.GcFlags.maxHeapSize - 2 * blocks);
- IF_DEBUG(gc, fprintf(stderr, "Near maximum heap size of 0x%x blocks, blocks = %d, adjusted to %d\n", RtsFlags.GcFlags.maxHeapSize, blocks, adjusted_blocks));
- pc_free = adjusted_blocks * 100 / RtsFlags.GcFlags.maxHeapSize;
- if (pc_free < RtsFlags.GcFlags.pcFreeHeap) /* might even be < 0 */ {
- heapOverflow();
- }
- blocks = adjusted_blocks;
-
- } else {
- blocks *= 2;
- if (blocks < RtsFlags.GcFlags.minAllocAreaSize) {
- blocks = RtsFlags.GcFlags.minAllocAreaSize;
- }
- }
-
- if (nursery_blocks < blocks) {
- IF_DEBUG(gc, fprintf(stderr, "Increasing size of nursery to %d blocks\n",
- blocks));
- g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
- } else {
- bdescr *next_bd;
-
- IF_DEBUG(gc, fprintf(stderr, "Decreasing size of nursery to %d blocks\n",
- blocks));
- for (bd = g0s0->blocks; nursery_blocks > blocks; nursery_blocks--) {
- next_bd = bd->link;
- freeGroup(bd);
- bd = next_bd;
- }
- g0s0->blocks = bd;
- }
-
- g0s0->n_blocks = nursery_blocks = blocks;
}
/* run through all the generations/steps and tidy up
*/
+ copied = new_blocks * BLOCK_SIZE_W;
for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
if (g <= N) {
/* Tidy the end of the to-space chains */
step->hp_bd->free = step->hp;
step->hp_bd->link = NULL;
+ /* stats information: how much we copied */
+ if (g <= N) {
+ copied -= step->hp_bd->start + BLOCK_SIZE_W -
+ step->hp_bd->free;
+ }
}
/* for generations we collected... */
* between the maximum size of the oldest and youngest
* generations.
*
- * max_blocks = alloc_area_size +
- * (oldgen_max_blocks - alloc_area_size) * G
- * -----------------------------------------
- * oldest_gen
+ * max_blocks = oldgen_max_blocks * G
+ * ----------------------
+ * oldest_gen
*/
if (g != 0) {
- generations[g].max_blocks =
- RtsFlags.GcFlags.minAllocAreaSize +
- (((oldest_gen->max_blocks - RtsFlags.GcFlags.minAllocAreaSize) * g)
- / (RtsFlags.GcFlags.generations-1));
+#if 0
+ generations[g].max_blocks = (oldest_gen->max_blocks * g)
+ / (RtsFlags.GcFlags.generations-1);
+#endif
+ generations[g].max_blocks = oldest_gen->max_blocks;
}
/* for older generations... */
}
}
+ /* Guess the amount of live data for stats. */
+ live = calcLive();
+
+ /* Free the small objects allocated via allocate(), since this will
+ * all have been copied into G0S1 now.
+ */
+ if (small_alloc_list != NULL) {
+ freeChain(small_alloc_list);
+ }
+ small_alloc_list = NULL;
+ alloc_blocks = 0;
+ alloc_Hp = NULL;
+ alloc_HpLim = NULL;
+ alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize;
+
/* Two-space collector:
* Free the old to-space, and estimate the amount of live data.
*/
if (RtsFlags.GcFlags.generations == 1) {
+ nat blocks;
+
if (old_to_space != NULL) {
freeChain(old_to_space);
}
- live = g0s0->to_blocks * BLOCK_SIZE_W +
- ((lnat)g0s0->hp_bd->free - (lnat)g0s0->hp_bd->start) / sizeof(W_);
+ for (bd = g0s0->to_space; bd != NULL; bd = bd->link) {
+ bd->evacuated = 0; /* now from-space */
+ }
- /* Generational collector:
- * estimate the amount of live data.
- */
+ /* For a two-space collector, we need to resize the nursery. */
+
+ /* set up a new nursery. Allocate a nursery size based on a
+ * function of the amount of live data (currently a factor of 2,
+ * should be configurable (ToDo)). Use the blocks from the old
+ * nursery if possible, freeing up any left over blocks.
+ *
+ * If we get near the maximum heap size, then adjust our nursery
+ * size accordingly. If the nursery is the same size as the live
+ * data (L), then we need 3L bytes. We can reduce the size of the
+ * nursery to bring the required memory down near 2L bytes.
+ *
+ * A normal 2-space collector would need 4L bytes to give the same
+ * performance we get from 3L bytes, reducing to the same
+ * performance at 2L bytes.
+ */
+ blocks = g0s0->to_blocks;
+
+ if ( blocks * RtsFlags.GcFlags.oldGenFactor * 2 >
+ RtsFlags.GcFlags.maxHeapSize ) {
+ int adjusted_blocks; /* signed on purpose */
+ int pc_free;
+
+ adjusted_blocks = (RtsFlags.GcFlags.maxHeapSize - 2 * blocks);
+ IF_DEBUG(gc, fprintf(stderr, "Near maximum heap size of 0x%x blocks, blocks = %d, adjusted to %d\n", RtsFlags.GcFlags.maxHeapSize, blocks, adjusted_blocks));
+ pc_free = adjusted_blocks * 100 / RtsFlags.GcFlags.maxHeapSize;
+ if (pc_free < RtsFlags.GcFlags.pcFreeHeap) /* might even be < 0 */ {
+ heapOverflow();
+ }
+ blocks = adjusted_blocks;
+
+ } else {
+ blocks *= RtsFlags.GcFlags.oldGenFactor;
+ if (blocks < RtsFlags.GcFlags.minAllocAreaSize) {
+ blocks = RtsFlags.GcFlags.minAllocAreaSize;
+ }
+ }
+ resizeNursery(blocks);
+
} else {
- live = 0;
- for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
- for (s = 0; s < generations[g].n_steps; s++) {
- /* approximate amount of live data (doesn't take into account slop
- * at end of each block). ToDo: this more accurately.
- */
- if (g == 0 && s == 0) { continue; }
- step = &generations[g].steps[s];
- live += step->n_blocks * BLOCK_SIZE_W +
- ((lnat)step->hp_bd->free -(lnat)step->hp_bd->start) / sizeof(W_);
+ /* Generational collector:
+ * If the user has given us a suggested heap size, adjust our
+ * allocation area to make best use of the memory available.
+ */
+
+ if (RtsFlags.GcFlags.heapSizeSuggestion) {
+ int blocks;
+ nat needed = calcNeeded(); /* approx blocks needed at next GC */
+
+ /* Guess how much will be live in generation 0 step 0 next time.
+ * A good approximation is the obtained by finding the
+ * percentage of g0s0 that was live at the last minor GC.
+ */
+ if (N == 0) {
+ g0s0_pcnt_kept = (new_blocks * 100) / g0s0->n_blocks;
+ }
+
+ /* Estimate a size for the allocation area based on the
+ * information available. We might end up going slightly under
+ * or over the suggested heap size, but we should be pretty
+ * close on average.
+ *
+ * Formula: suggested - needed
+ * ----------------------------
+ * 1 + g0s0_pcnt_kept/100
+ *
+ * where 'needed' is the amount of memory needed at the next
+ * collection for collecting all steps except g0s0.
+ */
+ blocks =
+ (((int)RtsFlags.GcFlags.heapSizeSuggestion - (int)needed) * 100) /
+ (100 + (int)g0s0_pcnt_kept);
+
+ if (blocks < (int)RtsFlags.GcFlags.minAllocAreaSize) {
+ blocks = RtsFlags.GcFlags.minAllocAreaSize;
}
+
+ resizeNursery((nat)blocks);
}
}
/* revert dead CAFs and update enteredCAFs list */
- revertDeadCAFs();
+ revert_dead_CAFs();
/* mark the garbage collected CAFs as dead */
#ifdef DEBUG
/* zero the scavenged static object list */
if (major_gc) {
- zeroStaticObjectList(scavenged_static_objects);
+ zero_static_object_list(scavenged_static_objects);
}
/* Reset the nursery
bd->free = bd->start;
ASSERT(bd->gen == g0);
ASSERT(bd->step == g0s0);
+ IF_DEBUG(sanity,memset(bd->start, 0xaa, BLOCK_SIZE));
}
current_nursery = g0s0->blocks;
- /* Free the small objects allocated via allocate(), since this will
- * all have been copied into G0S1 now.
- */
- if (small_alloc_list != NULL) {
- freeChain(small_alloc_list);
- }
- small_alloc_list = NULL;
- alloc_blocks = 0;
- alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize;
-
- /* start any pending finalisers */
- scheduleFinalisers(old_weak_ptr_list);
+ /* start any pending finalizers */
+ scheduleFinalizers(old_weak_ptr_list);
/* check sanity after GC */
-#ifdef DEBUG
- if (RtsFlags.GcFlags.generations == 1) {
- IF_DEBUG(sanity, checkHeap(g0s0->to_space, NULL));
- IF_DEBUG(sanity, checkChain(g0s0->large_objects));
- } else {
-
- for (g = 0; g <= N; g++) {
- for (s = 0; s < generations[g].n_steps; s++) {
- if (g == 0 && s == 0) { continue; }
- IF_DEBUG(sanity, checkHeap(generations[g].steps[s].blocks, NULL));
- }
- }
- for (g = N+1; g < RtsFlags.GcFlags.generations; g++) {
- for (s = 0; s < generations[g].n_steps; s++) {
- IF_DEBUG(sanity, checkHeap(generations[g].steps[s].blocks,
- generations[g].steps[s].blocks->start));
- IF_DEBUG(sanity, checkChain(generations[g].steps[s].large_objects));
- }
- }
- IF_DEBUG(sanity, checkFreeListSanity());
- }
-#endif
+ IF_DEBUG(sanity, checkSanity(N));
+ /* extra GC trace info */
IF_DEBUG(gc, stat_describe_gens());
#ifdef DEBUG
IF_DEBUG(sanity, memInventory());
/* ok, GC over: tell the stats department what happened. */
- stat_endGC(allocated, collected, live, N);
+ stat_endGC(allocated, collected, live, copied, N);
}
/* -----------------------------------------------------------------------------
new live weak pointers, then all the currently unreachable ones are
dead.
- For generational GC: we just don't try to finalise weak pointers in
+ For generational GC: we just don't try to finalize weak pointers in
older generations than the one we're collecting. This could
probably be optimised by keeping per-generation lists of weak
pointers, but for a few weak pointers this scheme will work.
traverse_weak_ptr_list(void)
{
StgWeak *w, **last_w, *next_w;
- StgClosure *target;
- const StgInfoTable *info;
+ StgClosure *new;
rtsBool flag = rtsFalse;
if (weak_done) { return rtsFalse; }
- /* doesn't matter where we evacuate values/finalisers to, since
+ /* doesn't matter where we evacuate values/finalizers to, since
* these pointers are treated as roots (iff the keys are alive).
*/
evac_gen = 0;
last_w = &old_weak_ptr_list;
for (w = old_weak_ptr_list; w; w = next_w) {
- target = w->key;
- loop:
- /* ignore weak pointers in older generations */
- if (!LOOKS_LIKE_STATIC(target) && Bdescr((P_)target)->gen->no > N) {
- IF_DEBUG(weak, fprintf(stderr,"Weak pointer still alive (in old gen) at %p\n", w));
- /* remove this weak ptr from the old_weak_ptr list */
- *last_w = w->link;
- /* and put it on the new weak ptr list */
- next_w = w->link;
- w->link = weak_ptr_list;
- weak_ptr_list = w;
- flag = rtsTrue;
+
+ /* First, this weak pointer might have been evacuated. If so,
+ * remove the forwarding pointer from the weak_ptr_list.
+ */
+ if (get_itbl(w)->type == EVACUATED) {
+ w = (StgWeak *)((StgEvacuated *)w)->evacuee;
+ *last_w = w;
+ }
+
+ /* There might be a DEAD_WEAK on the list if finalizeWeak# was
+ * called on a live weak pointer object. Just remove it.
+ */
+ if (w->header.info == &DEAD_WEAK_info) {
+ next_w = ((StgDeadWeak *)w)->link;
+ *last_w = next_w;
continue;
}
- info = get_itbl(target);
- switch (info->type) {
-
- case IND:
- case IND_STATIC:
- case IND_PERM:
- case IND_OLDGEN: /* rely on compatible layout with StgInd */
- case IND_OLDGEN_PERM:
- /* follow indirections */
- target = ((StgInd *)target)->indirectee;
- goto loop;
+ ASSERT(get_itbl(w)->type == WEAK);
- case EVACUATED:
- /* If key is alive, evacuate value and finaliser and
- * place weak ptr on new weak ptr list.
- */
- IF_DEBUG(weak, fprintf(stderr,"Weak pointer still alive at %p\n", w));
- w->key = ((StgEvacuated *)target)->evacuee;
+ /* Now, check whether the key is reachable.
+ */
+ if ((new = isAlive(w->key))) {
+ w->key = new;
+ /* evacuate the value and finalizer */
w->value = evacuate(w->value);
- w->finaliser = evacuate(w->finaliser);
-
+ w->finalizer = evacuate(w->finalizer);
/* remove this weak ptr from the old_weak_ptr list */
*last_w = w->link;
-
/* and put it on the new weak ptr list */
next_w = w->link;
w->link = weak_ptr_list;
weak_ptr_list = w;
flag = rtsTrue;
- break;
-
- default: /* key is dead */
+ IF_DEBUG(weak, fprintf(stderr,"Weak pointer still alive at %p -> %p\n", w, w->key));
+ continue;
+ }
+ else {
last_w = &(w->link);
next_w = w->link;
- break;
+ continue;
}
}
/* If we didn't make any changes, then we can go round and kill all
* the dead weak pointers. The old_weak_ptr list is used as a list
- * of pending finalisers later on.
+ * of pending finalizers later on.
*/
if (flag == rtsFalse) {
for (w = old_weak_ptr_list; w; w = w->link) {
w->value = evacuate(w->value);
- w->finaliser = evacuate(w->finaliser);
+ w->finalizer = evacuate(w->finalizer);
}
weak_done = rtsTrue;
}
return rtsTrue;
}
+/* -----------------------------------------------------------------------------
+ After GC, the live weak pointer list may have forwarding pointers
+ on it, because a weak pointer object was evacuated after being
+ moved to the live weak pointer list. We remove those forwarding
+ pointers here.
+
+ Also, we don't consider weak pointer objects to be reachable, but
+ we must nevertheless consider them to be "live" and retain them.
+ Therefore any weak pointer objects which haven't as yet been
+ evacuated need to be evacuated now.
+ -------------------------------------------------------------------------- */
+
+static void
+cleanup_weak_ptr_list ( void )
+{
+ StgWeak *w, **last_w;
+
+ last_w = &weak_ptr_list;
+ for (w = weak_ptr_list; w; w = w->link) {
+
+ if (get_itbl(w)->type == EVACUATED) {
+ w = (StgWeak *)((StgEvacuated *)w)->evacuee;
+ *last_w = w;
+ }
+
+ if (Bdescr((P_)w)->evacuated == 0) {
+ (StgClosure *)w = evacuate((StgClosure *)w);
+ *last_w = w;
+ }
+ last_w = &(w->link);
+ }
+}
+
+/* -----------------------------------------------------------------------------
+ isAlive determines whether the given closure is still alive (after
+ a garbage collection) or not. It returns the new address of the
+ closure if it is alive, or NULL otherwise.
+ -------------------------------------------------------------------------- */
+
+StgClosure *
+isAlive(StgClosure *p)
+{
+ StgInfoTable *info;
+
+ while (1) {
+
+ info = get_itbl(p);
+
+ /* ToDo: for static closures, check the static link field.
+ * Problem here is that we sometimes don't set the link field, eg.
+ * for static closures with an empty SRT or CONSTR_STATIC_NOCAFs.
+ */
+
+ /* ignore closures in generations that we're not collecting. */
+ if (LOOKS_LIKE_STATIC(p) || Bdescr((P_)p)->gen->no > N) {
+ return p;
+ }
+
+ switch (info->type) {
+
+ case IND:
+ case IND_STATIC:
+ case IND_PERM:
+ case IND_OLDGEN: /* rely on compatible layout with StgInd */
+ case IND_OLDGEN_PERM:
+ /* follow indirections */
+ p = ((StgInd *)p)->indirectee;
+ continue;
+
+ case EVACUATED:
+ /* alive! */
+ return ((StgEvacuated *)p)->evacuee;
+
+ default:
+ /* dead. */
+ return NULL;
+ }
+ }
+}
+
StgClosure *
MarkRoot(StgClosure *root)
{
- root = evacuate(root);
- return root;
+ return evacuate(root);
}
-static inline void addBlock(step *step)
+static void addBlock(step *step)
{
bdescr *bd = allocBlock();
bd->gen = step->gen;
step->hpLim = step->hp + BLOCK_SIZE_W;
step->hp_bd = bd;
step->to_blocks++;
+ new_blocks++;
+}
+
+static __inline__ void
+upd_evacuee(StgClosure *p, StgClosure *dest)
+{
+ p->header.info = &EVACUATED_info;
+ ((StgEvacuated *)p)->evacuee = dest;
}
static __inline__ StgClosure *
-copy(StgClosure *src, nat size, bdescr *bd)
+copy(StgClosure *src, nat size, step *step)
{
- step *step;
P_ to, from, dest;
+ TICK_GC_WORDS_COPIED(size);
/* Find out where we're going, using the handy "to" pointer in
* the step of the source object. If it turns out we need to
* evacuate to an older generation, adjust it here (see comment
* by evacuate()).
*/
- step = bd->step->to;
if (step->gen->no < evac_gen) {
+#ifdef NO_EAGER_PROMOTION
+ failed_to_evac = rtsTrue;
+#else
step = &generations[evac_gen].steps[0];
+#endif
}
/* chain a new block onto the to-space for the destination step if
addBlock(step);
}
- dest = step->hp;
- step->hp += size;
- for(to = dest, from = (P_)src; size>0; --size) {
+ for(to = step->hp, from = (P_)src; size>0; --size) {
*to++ = *from++;
}
+
+ dest = step->hp;
+ step->hp = to;
+ upd_evacuee(src,(StgClosure *)dest);
return (StgClosure *)dest;
}
*/
static __inline__ StgClosure *
-copyPart(StgClosure *src, nat size_to_reserve, nat size_to_copy, bdescr *bd)
+copyPart(StgClosure *src, nat size_to_reserve, nat size_to_copy, step *step)
{
- step *step;
P_ dest, to, from;
- step = bd->step->to;
+ TICK_GC_WORDS_COPIED(size_to_copy);
if (step->gen->no < evac_gen) {
+#ifdef NO_EAGER_PROMOTION
+ failed_to_evac = rtsTrue;
+#else
step = &generations[evac_gen].steps[0];
+#endif
}
if (step->hp + size_to_reserve >= step->hpLim) {
addBlock(step);
}
- dest = step->hp;
- step->hp += size_to_reserve;
- for(to = dest, from = (P_)src; size_to_copy>0; --size_to_copy) {
+ for(to = step->hp, from = (P_)src; size_to_copy>0; --size_to_copy) {
*to++ = *from++;
}
+ dest = step->hp;
+ step->hp += size_to_reserve;
+ upd_evacuee(src,(StgClosure *)dest);
return (StgClosure *)dest;
}
-static __inline__ void
-upd_evacuee(StgClosure *p, StgClosure *dest)
-{
- StgEvacuated *q = (StgEvacuated *)p;
-
- SET_INFO(q,&EVACUATED_info);
- q->evacuee = dest;
-}
-
-/* -----------------------------------------------------------------------------
- Evacuate a mutable object
-
- If we evacuate a mutable object to an old generation, cons the
- object onto the older generation's mutable list.
- -------------------------------------------------------------------------- */
-
-static inline void
-evacuate_mutable(StgMutClosure *c)
-{
- bdescr *bd;
-
- bd = Bdescr((P_)c);
- if (bd->gen->no > 0) {
- c->mut_link = bd->gen->mut_list;
- bd->gen->mut_list = c;
- }
-}
-
/* -----------------------------------------------------------------------------
Evacuate a large object
*/
if (bd->gen->no < evac_gen) {
failed_to_evac = rtsTrue;
+ TICK_GC_FAILED_PROMOTION();
}
return;
}
*/
step = bd->step->to;
if (step->gen->no < evac_gen) {
+#ifdef NO_EAGER_PROMOTION
+ failed_to_evac = rtsTrue;
+#else
step = &generations[evac_gen].steps[0];
+#endif
}
bd->step = step;
bd->evacuated = 1;
if (mutable) {
- evacuate_mutable((StgMutClosure *)p);
+ recordMutable((StgMutClosure *)p);
}
}
SET_HDR(q,&MUT_CONS_info,CCS_GC);
q->var = ptr;
- evacuate_mutable((StgMutClosure *)q);
+ recordOldToNewPtrs((StgMutClosure *)q);
return (StgClosure *)q;
}
{
StgClosure *to;
bdescr *bd = NULL;
+ step *step;
const StgInfoTable *info;
loop:
if (bd->gen->no < evac_gen) {
/* nope */
failed_to_evac = rtsTrue;
+ TICK_GC_FAILED_PROMOTION();
}
return q;
}
+ step = bd->step->to;
}
/* make sure the info pointer is into text space */
switch (info -> type) {
case BCO:
- to = copy(q,bco_sizeW(stgCast(StgBCO*,q)),bd);
- upd_evacuee(q,to);
- return to;
+ return copy(q,bco_sizeW(stgCast(StgBCO*,q)),step);
case MUT_VAR:
+ ASSERT(q->header.info != &MUT_CONS_info);
case MVAR:
- to = copy(q,sizeW_fromITBL(info),bd);
- upd_evacuee(q,to);
- evacuate_mutable((StgMutClosure *)to);
+ to = copy(q,sizeW_fromITBL(info),step);
+ recordMutable((StgMutClosure *)to);
return to;
+ case FUN_1_0:
+ case FUN_0_1:
+ case CONSTR_1_0:
+ case CONSTR_0_1:
+ return copy(q,sizeofW(StgHeader)+1,step);
+
+ case THUNK_1_0: /* here because of MIN_UPD_SIZE */
+ case THUNK_0_1:
+ case THUNK_1_1:
+ case THUNK_0_2:
+ case THUNK_2_0:
+#ifdef NO_PROMOTE_THUNKS
+ if (bd->gen->no == 0 &&
+ bd->step->no != 0 &&
+ bd->step->no == bd->gen->n_steps-1) {
+ step = bd->step;
+ }
+#endif
+ return copy(q,sizeofW(StgHeader)+2,step);
+
+ case FUN_1_1:
+ case FUN_0_2:
+ case FUN_2_0:
+ case CONSTR_1_1:
+ case CONSTR_0_2:
+ case CONSTR_2_0:
+ return copy(q,sizeofW(StgHeader)+2,step);
+
case FUN:
case THUNK:
case CONSTR:
case CAF_ENTERED:
case WEAK:
case FOREIGN:
- to = copy(q,sizeW_fromITBL(info),bd);
- upd_evacuee(q,to);
- return to;
+ case STABLE_NAME:
+ return copy(q,sizeW_fromITBL(info),step);
case CAF_BLACKHOLE:
case BLACKHOLE:
- to = copyPart(q,BLACKHOLE_sizeW(),sizeofW(StgHeader),bd);
- upd_evacuee(q,to);
- return to;
+ return copyPart(q,BLACKHOLE_sizeW(),sizeofW(StgHeader),step);
case BLACKHOLE_BQ:
- to = copy(q,BLACKHOLE_sizeW(),bd);
- upd_evacuee(q,to);
- evacuate_mutable((StgMutClosure *)to);
+ to = copy(q,BLACKHOLE_sizeW(),step);
+ recordMutable((StgMutClosure *)to);
return to;
case THUNK_SELECTOR:
selectee_info = get_itbl(selectee);
switch (selectee_info->type) {
case CONSTR:
+ case CONSTR_1_0:
+ case CONSTR_0_1:
+ case CONSTR_2_0:
+ case CONSTR_1_1:
+ case CONSTR_0_2:
case CONSTR_STATIC:
{
StgNat32 offset = info->layout.selector_offset;
if (bd->evacuated) {
if (bd->gen->no < evac_gen) {
failed_to_evac = rtsTrue;
+ TICK_GC_FAILED_PROMOTION();
}
return q;
}
goto selector_loop;
case THUNK:
+ case THUNK_1_0:
+ case THUNK_0_1:
+ case THUNK_2_0:
+ case THUNK_1_1:
+ case THUNK_0_2:
case THUNK_STATIC:
case THUNK_SELECTOR:
/* aargh - do recursively???? */
barf("evacuate: THUNK_SELECTOR: strange selectee");
}
}
- to = copy(q,THUNK_SELECTOR_sizeW(),bd);
- upd_evacuee(q,to);
- return to;
+ return copy(q,THUNK_SELECTOR_sizeW(),step);
case IND:
case IND_OLDGEN:
case PAP:
/* these are special - the payload is a copy of a chunk of stack,
tagging and all. */
- to = copy(q,pap_sizeW(stgCast(StgPAP*,q)),bd);
- upd_evacuee(q,to);
- return to;
+ return copy(q,pap_sizeW(stgCast(StgPAP*,q)),step);
case EVACUATED:
/* Already evacuated, just return the forwarding address.
if (Bdescr((P_)p)->gen->no < evac_gen) {
/* fprintf(stderr,"evac failed!\n");*/
failed_to_evac = rtsTrue;
- }
+ TICK_GC_FAILED_PROMOTION();
+ }
}
return ((StgEvacuated*)q)->evacuee;
- case MUT_ARR_WORDS:
case ARR_WORDS:
{
nat size = arr_words_sizeW(stgCast(StgArrWords*,q));
return q;
} else {
/* just copy the block */
- to = copy(q,size,bd);
- upd_evacuee(q,to);
- return to;
+ return copy(q,size,step);
}
}
to = q;
} else {
/* just copy the block */
- to = copy(q,size,bd);
- upd_evacuee(q,to);
+ to = copy(q,size,step);
if (info->type == MUT_ARR_PTRS) {
- evacuate_mutable((StgMutClosure *)to);
+ recordMutable((StgMutClosure *)to);
}
}
return to;
* list it contains.
*/
} else {
- StgTSO *new_tso = (StgTSO *)copy((StgClosure *)tso,tso_sizeW(tso),bd);
+ StgTSO *new_tso = (StgTSO *)copy((StgClosure *)tso,tso_sizeW(tso),step);
diff = (StgPtr)new_tso - (StgPtr)tso; /* In *words* */
new_tso->splim = (StgPtr)new_tso->splim + diff;
relocate_TSO(tso, new_tso);
- upd_evacuee(q,(StgClosure *)new_tso);
- evacuate_mutable((StgMutClosure *)new_tso);
+ recordMutable((StgMutClosure *)new_tso);
return (StgClosure *)new_tso;
}
}
break;
}
+ case THUNK_2_0:
+ case FUN_2_0:
+ scavenge_srt(info);
+ case CONSTR_2_0:
+ ((StgClosure *)p)->payload[1] = evacuate(((StgClosure *)p)->payload[1]);
+ ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case THUNK_1_0:
+ scavenge_srt(info);
+ ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2; /* MIN_UPD_SIZE */
+ break;
+
+ case FUN_1_0:
+ scavenge_srt(info);
+ case CONSTR_1_0:
+ ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 1;
+ break;
+
+ case THUNK_0_1:
+ scavenge_srt(info);
+ p += sizeofW(StgHeader) + 2; /* MIN_UPD_SIZE */
+ break;
+
+ case FUN_0_1:
+ scavenge_srt(info);
+ case CONSTR_0_1:
+ p += sizeofW(StgHeader) + 1;
+ break;
+
+ case THUNK_0_2:
+ case FUN_0_2:
+ scavenge_srt(info);
+ case CONSTR_0_2:
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case THUNK_1_1:
+ case FUN_1_1:
+ scavenge_srt(info);
+ case CONSTR_1_1:
+ ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2;
+ break;
+
case FUN:
case THUNK:
scavenge_srt(info);
case CONSTR:
case WEAK:
case FOREIGN:
+ case STABLE_NAME:
case IND_PERM:
case IND_OLDGEN_PERM:
case CAF_UNENTERED:
evacuate((StgClosure *)bh->blocking_queue);
if (failed_to_evac) {
failed_to_evac = rtsFalse;
- evacuate_mutable((StgMutClosure *)bh);
+ recordMutable((StgMutClosure *)bh);
}
p += BLACKHOLE_sizeW();
break;
}
case ARR_WORDS:
- case MUT_ARR_WORDS:
/* nothing to follow */
p += arr_words_sizeW(stgCast(StgArrWords*,p));
break;
}
if (failed_to_evac) {
/* we can do this easier... */
- evacuate_mutable((StgMutClosure *)start);
+ recordMutable((StgMutClosure *)start);
failed_to_evac = rtsFalse;
}
break;
objects can have this property.
-------------------------------------------------------------------------- */
static rtsBool
-scavenge_one(StgPtr p)
+scavenge_one(StgClosure *p)
{
StgInfoTable *info;
rtsBool no_luck;
- ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO((StgClosure *)p))
- || IS_HUGS_CONSTR_INFO(GET_INFO((StgClosure *)p))));
+ ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p))
+ || IS_HUGS_CONSTR_INFO(GET_INFO(p))));
- info = get_itbl((StgClosure *)p);
+ info = get_itbl(p);
switch (info -> type) {
case FUN:
+ case FUN_1_0: /* hardly worth specialising these guys */
+ case FUN_0_1:
+ case FUN_1_1:
+ case FUN_0_2:
+ case FUN_2_0:
case THUNK:
+ case THUNK_1_0:
+ case THUNK_0_1:
+ case THUNK_1_1:
+ case THUNK_0_2:
+ case THUNK_2_0:
case CONSTR:
+ case CONSTR_1_0:
+ case CONSTR_0_1:
+ case CONSTR_1_1:
+ case CONSTR_0_2:
+ case CONSTR_2_0:
case WEAK:
case FOREIGN:
case IND_PERM:
case CAF_UNENTERED:
case CAF_ENTERED:
{
- StgPtr end;
+ StgPtr q, end;
- end = (P_)((StgClosure *)p)->payload + info->layout.payload.ptrs;
- for (p = (P_)((StgClosure *)p)->payload; p < end; p++) {
- (StgClosure *)*p = evacuate((StgClosure *)*p);
+ end = (P_)p->payload + info->layout.payload.ptrs;
+ for (q = (P_)p->payload; q < end; q++) {
+ (StgClosure *)*q = evacuate((StgClosure *)*q);
}
break;
}
{
StgSelector *s = (StgSelector *)p;
s->selectee = evacuate(s->selectee);
- break;
+ break;
}
case AP_UPD: /* same as PAPs */
* evacuate the function pointer too...
*/
{
- StgPAP* pap = stgCast(StgPAP*,p);
+ StgPAP* pap = (StgPAP *)p;
pap->fun = evacuate(pap->fun);
scavenge_stack((P_)pap->payload, (P_)pap->payload + pap->n_args);
remove non-mutable objects from the mutable list at this point.
-------------------------------------------------------------------------- */
-static StgMutClosure *
-scavenge_mutable_list(StgMutClosure *p, nat gen)
+static void
+scavenge_mut_once_list(generation *gen)
{
StgInfoTable *info;
- StgMutClosure *start;
- StgMutClosure **prev;
+ StgMutClosure *p, *next, *new_list;
- evac_gen = 0;
+ p = gen->mut_once_list;
+ new_list = END_MUT_LIST;
+ next = p->mut_link;
+
+ evac_gen = gen->no;
+ failed_to_evac = rtsFalse;
+
+ for (; p != END_MUT_LIST; p = next, next = p->mut_link) {
+
+ /* make sure the info pointer is into text space */
+ ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p))
+ || IS_HUGS_CONSTR_INFO(GET_INFO(p))));
+
+ info = get_itbl(p);
+ switch(info->type) {
+
+ case IND_OLDGEN:
+ case IND_OLDGEN_PERM:
+ case IND_STATIC:
+ /* Try to pull the indirectee into this generation, so we can
+ * remove the indirection from the mutable list.
+ */
+ ((StgIndOldGen *)p)->indirectee =
+ evacuate(((StgIndOldGen *)p)->indirectee);
+
+#if 0
+ /* Debugging code to print out the size of the thing we just
+ * promoted
+ */
+ {
+ StgPtr start = gen->steps[0].scan;
+ bdescr *start_bd = gen->steps[0].scan_bd;
+ nat size = 0;
+ scavenge(&gen->steps[0]);
+ if (start_bd != gen->steps[0].scan_bd) {
+ size += (P_)BLOCK_ROUND_UP(start) - start;
+ start_bd = start_bd->link;
+ while (start_bd != gen->steps[0].scan_bd) {
+ size += BLOCK_SIZE_W;
+ start_bd = start_bd->link;
+ }
+ size += gen->steps[0].scan -
+ (P_)BLOCK_ROUND_DOWN(gen->steps[0].scan);
+ } else {
+ size = gen->steps[0].scan - start;
+ }
+ fprintf(stderr,"evac IND_OLDGEN: %d bytes\n", size * sizeof(W_));
+ }
+#endif
+
+ /* failed_to_evac might happen if we've got more than two
+ * generations, we're collecting only generation 0, the
+ * indirection resides in generation 2 and the indirectee is
+ * in generation 1.
+ */
+ if (failed_to_evac) {
+ failed_to_evac = rtsFalse;
+ p->mut_link = new_list;
+ new_list = p;
+ } else {
+ /* the mut_link field of an IND_STATIC is overloaded as the
+ * static link field too (it just so happens that we don't need
+ * both at the same time), so we need to NULL it out when
+ * removing this object from the mutable list because the static
+ * link fields are all assumed to be NULL before doing a major
+ * collection.
+ */
+ p->mut_link = NULL;
+ }
+ continue;
+
+ case MUT_VAR:
+ /* MUT_CONS is a kind of MUT_VAR, except it that we try to remove
+ * it from the mutable list if possible by promoting whatever it
+ * points to.
+ */
+ ASSERT(p->header.info == &MUT_CONS_info);
+ if (scavenge_one(((StgMutVar *)p)->var) == rtsTrue) {
+ /* didn't manage to promote everything, so put the
+ * MUT_CONS back on the list.
+ */
+ p->mut_link = new_list;
+ new_list = p;
+ }
+ continue;
+
+ default:
+ /* shouldn't have anything else on the mutables list */
+ barf("scavenge_mut_once_list: strange object?");
+ }
+ }
- prev = &start;
- start = p;
+ gen->mut_once_list = new_list;
+}
+
+
+static void
+scavenge_mutable_list(generation *gen)
+{
+ StgInfoTable *info;
+ StgMutClosure *p, *next;
+
+ p = gen->saved_mut_list;
+ next = p->mut_link;
+ evac_gen = 0;
failed_to_evac = rtsFalse;
- for (; p != END_MUT_LIST; p = *prev) {
+ for (; p != END_MUT_LIST; p = next, next = p->mut_link) {
/* make sure the info pointer is into text space */
ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p))
StgPtr end, q;
end = (P_)p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- evac_gen = gen;
+ evac_gen = gen->no;
for (q = (P_)((StgMutArrPtrs *)p)->payload; q < end; q++) {
(StgClosure *)*q = evacuate((StgClosure *)*q);
}
if (failed_to_evac) {
failed_to_evac = rtsFalse;
- prev = &p->mut_link;
- } else {
- *prev = p->mut_link;
- }
+ p->mut_link = gen->mut_list;
+ gen->mut_list = p;
+ }
continue;
}
case MUT_ARR_PTRS:
/* follow everything */
- prev = &p->mut_link;
+ p->mut_link = gen->mut_list;
+ gen->mut_list = p;
{
StgPtr end, q;
* it from the mutable list if possible by promoting whatever it
* points to.
*/
- if (p->header.info == &MUT_CONS_info) {
- evac_gen = gen;
- if (scavenge_one((P_)((StgMutVar *)p)->var) == rtsTrue) {
- /* didn't manage to promote everything, so leave the
- * MUT_CONS on the list.
- */
- prev = &p->mut_link;
- } else {
- *prev = p->mut_link;
- }
- evac_gen = 0;
- } else {
- ((StgMutVar *)p)->var = evacuate(((StgMutVar *)p)->var);
- prev = &p->mut_link;
- }
+ ASSERT(p->header.info != &MUT_CONS_info);
+ ((StgMutVar *)p)->var = evacuate(((StgMutVar *)p)->var);
+ p->mut_link = gen->mut_list;
+ gen->mut_list = p;
continue;
case MVAR:
(StgClosure *)mvar->head = evacuate((StgClosure *)mvar->head);
(StgClosure *)mvar->tail = evacuate((StgClosure *)mvar->tail);
(StgClosure *)mvar->value = evacuate((StgClosure *)mvar->value);
- prev = &p->mut_link;
+ p->mut_link = gen->mut_list;
+ gen->mut_list = p;
continue;
}
* point to some younger objects (because we set evac_gen to 0
* above).
*/
- prev = &tso->mut_link;
+ tso->mut_link = gen->mut_list;
+ gen->mut_list = (StgMutClosure *)tso;
continue;
}
- case IND_OLDGEN:
- case IND_OLDGEN_PERM:
- case IND_STATIC:
- /* Try to pull the indirectee into this generation, so we can
- * remove the indirection from the mutable list.
- */
- evac_gen = gen;
- ((StgIndOldGen *)p)->indirectee =
- evacuate(((StgIndOldGen *)p)->indirectee);
- evac_gen = 0;
-
- if (failed_to_evac) {
- failed_to_evac = rtsFalse;
- prev = &p->mut_link;
- } else {
- *prev = p->mut_link;
- /* the mut_link field of an IND_STATIC is overloaded as the
- * static link field too (it just so happens that we don't need
- * both at the same time), so we need to NULL it out when
- * removing this object from the mutable list because the static
- * link fields are all assumed to be NULL before doing a major
- * collection.
- */
- p->mut_link = NULL;
- }
- continue;
-
case BLACKHOLE_BQ:
{
StgBlockingQueue *bh = (StgBlockingQueue *)p;
(StgClosure *)bh->blocking_queue =
evacuate((StgClosure *)bh->blocking_queue);
- prev = &p->mut_link;
- break;
+ p->mut_link = gen->mut_list;
+ gen->mut_list = p;
+ continue;
}
default:
/* shouldn't have anything else on the mutables list */
- barf("scavenge_mutable_object: non-mutable object?");
+ barf("scavenge_mut_list: strange object?");
}
}
- return start;
}
static void
if (failed_to_evac) {
failed_to_evac = rtsFalse;
scavenged_static_objects = STATIC_LINK(info,p);
- ((StgMutClosure *)ind)->mut_link = oldest_gen->mut_list;
- oldest_gen->mut_list = (StgMutClosure *)ind;
+ ((StgMutClosure *)ind)->mut_link = oldest_gen->mut_once_list;
+ oldest_gen->mut_once_list = (StgMutClosure *)ind;
}
break;
}
continue;
} else {
bdescr *bd = Bdescr((P_)frame->updatee);
+ step *step;
if (bd->gen->no > N) {
if (bd->gen->no < evac_gen) {
failed_to_evac = rtsTrue;
}
continue;
}
+
+ /* Don't promote blackholes */
+ step = bd->step;
+ if (!(step->gen->no == 0 &&
+ step->no != 0 &&
+ step->no == step->gen->n_steps-1)) {
+ step = step->to;
+ }
+
switch (type) {
case BLACKHOLE:
case CAF_BLACKHOLE:
to = copyPart(frame->updatee, BLACKHOLE_sizeW(),
- sizeofW(StgHeader), bd);
- upd_evacuee(frame->updatee,to);
+ sizeofW(StgHeader), step);
frame->updatee = to;
continue;
case BLACKHOLE_BQ:
- to = copy(frame->updatee, BLACKHOLE_sizeW(), bd);
- upd_evacuee(frame->updatee,to);
+ to = copy(frame->updatee, BLACKHOLE_sizeW(), step);
frame->updatee = to;
- evacuate_mutable((StgMutClosure *)to);
+ recordMutable((StgMutClosure *)to);
continue;
default:
barf("scavenge_stack: UPDATE_FRAME updatee");
/* only certain objects can be "large"... */
case ARR_WORDS:
- case MUT_ARR_WORDS:
/* nothing to follow */
continue;
}
evac_gen = 0;
if (failed_to_evac) {
- evacuate_mutable((StgMutClosure *)start);
+ recordMutable((StgMutClosure *)start);
}
continue;
}
}
static void
-zeroStaticObjectList(StgClosure* first_static)
+zero_static_object_list(StgClosure* first_static)
{
StgClosure* p;
StgClosure* link;
* mutable list.
*/
static void
-zeroMutableList(StgMutClosure *first)
+zero_mutable_list( StgMutClosure *first )
{
StgMutClosure *next, *c;
}
}
-void revertDeadCAFs(void)
+void revert_dead_CAFs(void)
{
StgCAF* caf = enteredCAFs;
enteredCAFs = END_CAF_LIST;
break;
}
default:
- barf("revertDeadCAFs: enteredCAFs list corrupted");
+ barf("revert_dead_CAFs: enteredCAFs list corrupted");
}
caf = next;
}
/* if the thunk is already blackholed, it means we've also
* already blackholed the rest of the thunks on this stack,
* so we can stop early.
+ *
+ * The blackhole made for a CAF is a CAF_BLACKHOLE, so they
+ * don't interfere with this optimisation.
*/
+ if (bh->header.info == &BLACKHOLE_info) {
+ return;
+ }
- /* Don't for now: when we enter a CAF, we create a black hole on
- * the heap and make the update frame point to it. Thus the
- * above optimisation doesn't apply.
- */
- if (bh->header.info != &BLACKHOLE_info
- && bh->header.info != &BLACKHOLE_BQ_info
- && bh->header.info != &CAF_BLACKHOLE_info) {
+ if (bh->header.info != &BLACKHOLE_BQ_info &&
+ bh->header.info != &CAF_BLACKHOLE_info) {
SET_INFO(bh,&BLACKHOLE_info);
}
* added to the stack, rather than the way we see them in this
* walk. (It makes the next loop less confusing.)
*
- * Could stop if we find an update frame pointing to a black hole,
- * but see comment in threadLazyBlackHole().
+ * Stop if we find an update frame pointing to a black hole
+ * (see comment in threadLazyBlackHole()).
*/
next_frame = NULL;
frame->link = next_frame;
next_frame = frame;
frame = prev_frame;
+ if (get_itbl(frame)->type == UPDATE_FRAME
+ && frame->updatee->header.info == &BLACKHOLE_info) {
+ break;
+ }
}
/* Now, we're at the bottom. Frame points to the lowest update
*/
if (is_update_frame) {
StgBlockingQueue *bh = (StgBlockingQueue *)frame->updatee;
- if (bh->header.info != &BLACKHOLE_info
- && bh->header.info != &BLACKHOLE_BQ_info
- && bh->header.info != &CAF_BLACKHOLE_info
- ) {
+ if (bh->header.info != &BLACKHOLE_BQ_info &&
+ bh->header.info != &CAF_BLACKHOLE_info) {
SET_INFO(bh,&BLACKHOLE_info);
}
}
projects / ghc-hetmet.git / blobdiff